Choose the OME experience your organization is using:

The new OME experience doesn't require you to download a separate app. If your organization has updated to the latest OME capabilities, we recommend using Outlook for iOS for a seamless and secure experience reading Office 365 messages. See, How do I open a message secured by Office 365 Encryption for directions on viewing O365 protected messages in other email apps.

How to read, reply to, or forward protected messages from Office 365 in the iOS Mail app

Your IT department must allow "service-side decryption" for the iOS Mail app.

Note:Office 365 protected messages can only be read in the iOS Mail app if your admin has enabled "service-side decryption." This means that Office 365 will decrypt messages for you before it reaches your iOS Mail inbox.

When you reply to a message, Exchange Online will determine whether or not you have rights from your organization to do so.

If you have permission, Office 365 protects the message back to the sender. If you don't, or the message was sent as "View only" by the sender, you'll receive a Non-Delivery Report.

Note: The iOS Mail app is not capable of reading permissions from Exchange Online. Only after you attempt to reply or forward a protected message will Exchange Online be able to determine your permissions.

If your Office 365 organization hasn't yet moved to the new Office Message Encryption (OME) experience but OME is already enabled, then you'll have to download and use the OME Viewer app with your chosen email app to view protected messages.

Open the encrypted message in Outlook for iOS. When you open the message, you’ll see an attachment called message.html. Tap the message.html attachment.

In the message attachment, tap the arrow in the upper right-hand corner. Tap Open in… and then tap Copy to OME Viewer.

Note: In order to complete this step, you must have OME Viewer installed on your iPhone or iPad.

In the OME Viewer, tap Use a one-time passcode.

Note: You may see an option that says Sign In if you are viewing an older message that was sent in August or earlier. Simply continue with the steps outlined here by selecting Use a one-time passcode.

You’ll receive an email containing the passcode you need in Outlook for iOS. The email will be sent to the email address to which the original encrypted message was sent. Open the email and tap the passcode. If prompted to open in OME Viewer, tap Open.

Tip: If you don’t see an email from Microsoft Office 365 Message Encryption, check the Other tab in Outlook for iOS or your junk email box.

You will now be able to view your encrypted message, download any attachments, or reply with your own encrypted message.

Use OME Viewer with the built-in iOS Mail app

Open the encrypted message in the iOS Mail app. When you open the message, you’ll see an attachment called message.html. Tap the message.html attachment to open it.

In the message attachment, tap the top of your screen to display the actions bar. Now tap the arrow in the upper right-hand corner. Scroll right and select Copy to OME Viewer.

Note: In order to complete this step, you must have OME Viewer installed on your iPhone or iPad.

In the OME Viewer, tap Use a one-time passcode.

Note: You may see an option that says Sign In if you are viewing an older message that was sent in August or earlier. Simply continue with the steps outlined here by selecting Use a one-time passcode.

You’ll receive an email containing the passcode you need in your Mail app. The email will be sent to the email address to which the original encrypted message was sent. Open the email and tap the passcode. If prompted to open in OME Viewer, tap Open.

You will now be able to view your encrypted message, download any attachments, or reply with your own encrypted message.

Use OME Viewer with the Gmail app on iOS

Open the encrypted message in the Gmail app. When you open the message, you’ll see an attachment called message.html. Tap the message.html attachment to open it.

In the message attachment, tap the top of your screen to display the actions bar. Now tap the arrow in the upper right-hand corner. Scroll right and select Copy to OME Viewer.

Note: In order to complete this step, you must have OME Viewer installed on your iPhone or iPad.

In the OME Viewer, tap Use a one-time passcode.

Note: You may see an option that says Sign In if you are viewing an older message that was sent in August or earlier. Simply continue with the steps outlined here by selecting Use a one-time passcode.

You’ll receive an email containing the passcode you need in your Gmail app. The email will be sent to the email address to which the original encrypted message was sent. Open the email and tap the passcode. If prompted to open in OME Viewer, tap Open.

Tip: If you don’t see an email from Microsoft Office 365 Message Encryption, check your spam folder or filter options.

You will now be able to view your encrypted message, download any attachments, or reply with your own encrypted message.

Use OME Viewer with the Yahoo Mail app on iOS

Open the encrypted message in the Yahoo Mail app. When you open the message, you’ll see an attachment called message.html. Tap the message.html attachment to open it.

In the message attachment, tap the arrow in the upper right-hand corner. Tap Open in... and then tap Copy to OME Viewer.

Note: In order to complete this step, you must have OME Viewer installed on your iPhone or iPad.

In the OME Viewer, tap Use a one-time passcode.

Note: You may see an option that says Sign In if you are viewing an older message that was sent in August or earlier. Simply continue with the steps outlined here by selecting Use a one-time passcode.

You’ll receive an email containing the passcode you need in your Yahoo Mail app. The email will be sent to the email address to which the original encrypted message was sent. Open the email and tap the passcode. If prompted to open in OME Viewer, tap Open.

Tip: If you don’t see an email from Microsoft Office 365 Message Encryption, check your spam folder or filter options.

You will now be able to view your encrypted message, download any attachments, or reply with your own encrypted message.

Use OME Viewer with an email app on iOS

Open the encrypted message from the email app on your iPhone or iPad. When you open the message, you’ll see an attachment called message.html. Tap the message.html attachment to open it.

Choose Copy to OME Viewer.

Note: In order to complete this step, you must have OME Viewer installed on your iPhone or iPad.

In the OME Viewer, tap Use a one-time passcode.

Note: You may see an option that says Sign In if you are viewing an older message that was sent in August or earlier. Simply continue with the steps outlined here by selecting Use a one-time passcode.

You’ll receive an email containing the passcode. The email will be sent to the email address to which the original encrypted message was sent. Open the email and tap the passcode. If prompted to open in OME Viewer, tap Open.

Tip: If you don’t see an email from Microsoft Office 365 Message Encryption, check your spam folder or filter options.

You will now be able to view your encrypted message, download any attachments, or reply with your own encrypted message.

If your passcode is no longer valid because 15 minutes or more have passed, go through the steps above again to request a new passcode.

If you've clicked on the passcode and nothing has loaded, return to the passcode email and tap it again.

Why does my encrypted message email look different than the screenshots on this page? Organizations who use Office 365 Message Encryption are able to customize their messages to their recipients. While the email may look different according to the organization's branding, the general steps will be the same.